1. Field of the Invention
The present invention relates to a semiconductor device and, in particular, relates to a technique for detecting a defect of a capacitor.
2. Description of the Related Art
A semiconductor device is constructed by forming circuit elements such as a transistor, resistor or capacitor on a semiconductor substrate made of silicon or gallium arsenide and connecting the respective circuit elements through wirings. To easily inspect such semiconductor devices, it is general to use a DC (direct current) test, in which DC voltage and electric current is applied to a predetermined point of an integrated circuit formed on a semiconductor device and resulting electrical characteristics is measured to subsequently check go or no-go and to measure circuit characteristics.
Here is a case where a capacitor is formed on a semiconductor integrated circuit. The capacitor is essentially open (impedance is infinite) to a DC signal component. Accordingly, in performing a DC test, it would appear that the capacitor does not exist against the DC signal component. Accordingly, the DC test has a problem that an unexpected open state (that is, high-frequency open failure) due to a disconnection or manufacturing defect of a capacitor or wiring connected to the capacitor is difficult to detect.